[fpc-pascal] code optimization

[Jonas Maebe]

On 24 Sep 2010, at 14:35, Jonas Maebe wrote:

> On 24 Sep 2010, at 11:48, Adrian Veith wrote:
>
>> Register allocation is on a comparable level for both versions.
>
> Delphi keeps the "Bar" pointer in a register, while FPC spills it to  
> the stack. Because Bar is used in most of the most-executed  
> statements, this has a huge impact.

Correction: Delphi keeps the hidden parent frame pointer parameter in  
a register (which is required every time Bar is accessed), while FPC  
puts it on the stack. The end result is the same though: 1 extra  
memory access every time Bar or any other variable from the parent  
procedure is accessed.


Jonas